Low-water alarm.



PATENTED FEB. 18, 1908.

6 0 m M- Em A- R L BAH Mi EL Y AN GWm m WA m P P A 8 0 9 F/ 8 nm N Witnesses:

Attdrneys GEORGE YEATES, or MONTREAL, QUEBEC, cANAton.

Low-WATER enema.

Specification of Letters Patent.

Patented Feb. 18, 15398.

Application filed April 16. 1908 Serial Ko- 312,061

To all whom it may concern:

Be it known that I, Gnonen YEATES, a subject of theKing of Great'Britain, residing at the cityand district of Montreal, in the Province of Quebec, Canada, have invented certain new and useful Improvements in Low- Water Alarms and Detectors and I do here by declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art towhich it appertains to make and use the same.

My invention relates to low water alarms for steam boilers, particularlyv locomotive boilers; the object of my invention is to provide a device for giving an alarm when the water in a boiler is so low as to endan er the burning out of the crown sheet, and disc for indicating to an inspector that the water has been dangerously low even after the water has been replenished; a further object is to provide an easily attached device, so con structcd that when the water has become low, it may be replenished without dumping the fire and my invention consists-of the construction, combination and arrangement of parts, as herein illustrated, described, and claimed.

' In the acconnanying drawings, formin part of this app ication, I have illustrated one form of embodiment of my invention, in which drawings similar reference characters designate corresponding parts, and in which: Figure 1 is a transverse vertical section through a portion of a boiler; Fig. .2 i. a side elevation of a casin and stirrup forming part of my invention fhig. 3 is a side elevation of an audible alarm mechanism, and a device for indicating that the alarm has been turned oh; 1*" .4 is a side elevation of a fusible valve; and, l ig. 5 is a side elevation of a spring adapted to actuate the valve. .7

. Referring to the drawings, 1 designates a boiler having a crown sheet 2. The crown sheet 2 is provided with a suitable opening in.

which is disposed a fixed casing 3, havin screw-thrcads 4 adapted to engage the wal of the opening in the crown sheet.

Disposed on or formed integral. with the casing 3 is a stirru 5, provided with openin s 6, the object c which openings is to'provi efor the free movement. of the water through the stirrup, so that scales will not be formed therein and retard the movement of the hereinafter described valve.

Carried by the upper end of the stirrup 5 is rup; The plug '7 is rovided with aassage 9 therethrou h, the ower end of wh cli 'pnfi sac-e is normsilly closed by a valve 10, formed of any suitable fusible metal. The valve-1U 1s made of a length such that when it rests-on of the valve is provided with an enlargement- 11. Disposed around the valve is a spring 12, the u per end of which thrust's against the lower? .of which thrusts against the enlargement". 11.

The casing 3 and the stirrup 5 are so anrangedat a distance from the crown heet 2' that when the water in the boiler is so low as to endan er the cro wn sheet, the valve 10 will melt, and v will be forced away from the opening 9 to under the action of the Springfia plug 7, rorided with screw threads s adapted to engage the inner wall of the sucace of the plug 7, and the lower end permit the escape of steam through said passage.

Connected with the passage 9 is a pipe 13,

which extends through the wall of the r 1, a suitable stuiiing box 14, collar 15,:iiid' packing 16being used toinake a perfect joint. The outer end of the ipe 13 is provided with a valve 17, normal y open, adapted to' be actuated by a handle 18. Disposed around the extreme outer end of the pipe 13 is a collar 19, provided with a projectmglug 20. Formed 1n the lug 20 is an opening 21 adapted to receive theflexible members 22 of wire, which flexible members are disposed through an opening 23 in the handle 18, and have affixed on their ends a seal 24 of cornpressible metal adapted to receive the'imprint of an inspectors seal.

In connection with the pipe 13 beyond the valve 17 is a whistle 25, or other device adapted to give an audible alarm when steam esca es through the-pip: 13.

T e valve 10 having een withdrawn from the passage 9, as described, steam will esca e through the pipe 13, and give an alarm y means of the member 25, until the handle 18 of the valve 17 is turned, thereby breaking the seal 24. This cuts oil the escape of steam from the boiler, and the water therein may be re )lenished without renewing the valve 10. ut the seal 24 having been broken, the inspector can readily see that the fireman in charge of the boiler has permitted the water to become dan erously low at some time.

In making the casing 3 and the plug 7 -faced, I provide a construction which is readily attachable to an ordinary form of boiler.

Having thus fully described my invention,

what I im as new and desire Letters Patent, is:-

1. In combination with a boiler, a stirrup, ascrew-threaded opening in the crown sheet of said boiler, an extension on said stirrup provided with screw-threads adapted to engage the screw-threads of the aforesaid openmg in the crown sheet and hold the stirrup in operative position, an interior screwthreaded portion in said stirrup, a plug, a screw-threaded extension on said plug adapted to engage the interior screw'threaded portion of the stirrup, a passage through said plug, a spring-pressed fusible valve removably mounted within said stirrup and adapted to normally close the passage in the plug and to establish .oommumcation between the interior of the boiler and the passage by being fused when the water in the boiler falls below the danger level," an alarm and a passage connecting the aforesaid passage in the plug and said alarm.

tosecure by 2. In combination wlth a boiler, a stirrup,

a screw-threaded. opening in the crown sheet of said boiler, an e:"ension on said stirrup portion of the stirrup, a passage through said plug, a spring-pressed fusible valve removably mounted within said stirrup and adapted to normally close the passage in the p ug and to establish communlcation between theinterior of the boiler and the passage by. being fused when the water in the boiler falls' below the danger level, an alarm, a assage';

connecting the aforesaid passage in the plug and said alarm! and normally open, a valve controlling said connecting passage and normally inoperative and a sea on said valve to hold the same in inoperative osition and to indicate when said valve has een turned to operative position.

Inwitness whereof I have hereunto setmy hand in the presence of two witnesses.

GEORGE YEATES.

Witnesses C. C. OOUSINS, E. M. SLINEY. 

